Avoid numerical integration
Avoid numerical integration

This calculates the bilinear basis analytically using the incomplete
gamma function. Some temporary print statements are introduced in order
to verify how long the different steps take. Other changes include
calling sdpb properly, handling non-integer dimensions and generating a
few extra derivatives that were missing.

Signed-off-by: Connor Behan <89f96a099c47edae2e9c5a371cbf43991ac7aa8c@gmail.com>

cbehan/pycftboot